This invention relates to seals for flange faces and more particularly relates to sealing gaskets for such flange faces.
Gaskets for sealing flange faces together are well known in the art. Unfortunately readily removable and cost effective gaskets for sealing flange faces have not been as good as desired, especially when the flange faces have been glass coated and surround openings in vessels or conduits having corrosive contents which are under pressure, e.g. 300 psi or higher. Under such conditions seals between flange faces have often been known to leak or even blow out. Further such known gaskets require high seating loads which can cause glass lining failures. Such seals also require a large number of clamps or bolts around the seal area in order to maintain the high loads required. In addition such seals have required the use of flange thicknesses which are greater than desired because thick flanges have been necessary to withstand the high loads.
Known seals for glass and other smooth surfaces generally use gaskets having flat surfaces which can seal at almost any location on the surface. Such seals are not as sanitary as desirable for pharmaceutical and food applications due to cracks at the edge of the contact areas between the sealing flange and gasket which may harbor contamination because the actual seal may be formed at another location on the flat gasket surface.
It has been known to use O-rings to form seals between flange faces; however, grooves have been placed in the flange faces in order to position and retain the O-rings, especially when any significant pressure is involved. Such grooves still do not retain the O-rings as well as desired and such grooves cannot be practically placed in a glass coated flange surface.
It is therefore an object of the present invention to provide an improved gasket for flange faces to overcome disadvantages of gaskets for flange faces known to those skilled in the art.